Today | Weather | Wednesday, April 15, 2026

Weather in Castle Rock, Colorado

04:42 AM
Now
Cloudy Night
37° F
Feels Like 34°
Precipitation 4 %
Wind 7 mph
Humidity 56 %
Today
Cloudy Weather
Day 64°
Night 37°
Precipitation 1 %
Wind 9 mph
UV Index (0 - 11+) 8

Warning: High UV Index Today: 8

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

Castle Rock Weather Forecast Updated

16 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 15, 2025)

Day

72°

Night

32°

Air Quality in Castle Rock

NOW
35 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.77 µg/m³
PM10 1.03 µg/m³
O3 0.038 ppm
NO2 0.7 ppb
SO2 0 ppb
CO 0.10 ppm
NH3 7.11 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.50.77 µg/m³
PM101.03 µg/m³
O373.71 µg/m³
NO21.37 µg/m³
SO20.02 µg/m³
CO109.69 µg/m³
NH37.11 µg/m³
NO0 µg/m³